Exposure apparatus and exposure method

ABSTRACT

The present invention provides an exposure apparatus and an exposure method. The method comprises: utilizing an exposure light source to provide light rays to the photo-resist layer; and utilizing a reflective plate to reflect the light rays passing through the photo-resist layer and the transparent substrate back to the photo-resist layer. The present invention can reduce a line space of a pattern of the photo-resist layer.

FIELD OF THE INVENTION

The present invention relates to a field of an exposure technology, andmore particularly to an exposure apparatus and an exposure method.

BACKGROUND OF THE INVENTION

A photo-lithography technology has been widely applied in manufacturingprocesses of electrical products. With the use of the photo-lithographytechnology, a photo-resist is exposed to form different patterns.However, when a line space of a pattern of the photo-resist is toosmall, the photo-resist has a lower transmittance, and thus a portion ofthe photo-resist is not exposed and is still non-patterned. Therefore,after the photo-lithography process, the formed pattern can not meet therequirement of a predetermined pattern, and the performance of theelectrical products is limited.

Specifically, in many current electrical devices, such as liquid crystaldisplays (LCDs), the line space of the pattern thereof is required to bereduced continuously for promoting the performance of the electricaldevices.

As a result, it is necessary to provide an exposure apparatus and anexposure method to solve the problems existing in the conventionaltechnologies, as described above.

SUMMARY OF THE INVENTION

The present invention provides an exposure apparatus and an exposuremethod for reducing a line space of a pattern of a photo-resist layer.

A primary object of the present invention is to provide an exposureapparatus for exposing a photo-resist layer on a transparent substrate,and the exposure apparatus comprises: a mask disposed at one side of thephoto-resist layer; an exposure light source configured to provide lightrays to the photo-resist layer, wherein the light rays provided by theexposure light source pass through the mask to reach the photo-resistlayer; and a reflective plate disposed at an opposite side of thephoto-resist layer for reflecting the light rays passing through thephoto-resist layer and the transparent substrate back to thephoto-resist layer.

Another object of the present invention is to provide an exposure methodfor exposing a photo-resist layer on a transparent substrate, and theexposure method comprises the following steps: utilizing an exposurelight source to provide light rays to the photo-resist layer, whereinthe light rays provided by the exposure light source pass through themask to reach the photo-resist layer; and utilizing a reflective plateto reflect the light rays passing through the photo-resist layer and thetransparent substrate back to the photo-resist layer.

In one embodiment of the present invention, when utilizing thereflective plate to reflect the light rays, the transparent substrate iscarried on the reflective plate.

In one embodiment of the present invention, the mask includes at leastone transparent opening, and a width of the transparent opening is lessthan 3 um.

In one embodiment of the present invention, the width of the transparentopening is equal to or less than 2 um.

In one embodiment of the present invention, characterized in that: areflective surface of the reflective plate is a flat surface.

In one embodiment of the present invention, the reflective plateincludes a plurality of convex structures.

In one embodiment of the present invention, the reflective plateincludes a plurality of concave structures.

In one embodiment of the present invention, the reflective plate isparallel to the photo-resist layer on the transparent substrate whenexposing the photo-resist layer.

With the use of the exposure apparatus and the exposure method of thepresent invention, it can be ensured that an exposed portion of thephoto-resist layer can be patterned completely, so as to prevent thatthe photo-resist layer can not be expose sufficiently due to a smallline space or a high depth-to-width ratio. Therefore, by means of theexposure apparatus and the exposure method of the present invention, theline space of the desired pattern can be reduced for promoting theperformance of electrical devices.

The structure and the technical means adopted by the present inventionto achieve the above and other objects can be best understood byreferring to the following detailed description of the preferredembodiments and the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an exposure apparatus according toa first embodiment of the present invention;

FIG. 2 is a schematic diagram showing a patterned photo-resist layeraccording to the first embodiment of the present invention;

FIG. 3 is a schematic diagram showing an etched transparent electrodelayer according to the first embodiment of the present invention;

FIG. 4 is a schematic diagram showing an exposure apparatus according toa second embodiment of the present invention; and

FIG. 5 is a schematic diagram showing an exposure apparatus according toa third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following embodiments are referring to the accompanying drawings forexemplifying specific implementable embodiments of the presentinvention. Furthermore, directional terms described by the presentinvention, such as upper, lower, front, back, left, right, inner, outer,side and etc., are only directions by referring to the accompanyingdrawings, and thus the used directional terms are used to describe andunderstand the present invention, but the present invention is notlimited thereto.

In the drawings, structure-like elements are labeled with like referencenumerals.

Referring to FIG. 1, a schematic diagram showing an exposure apparatusaccording to a first embodiment of the present invention is illustrated.The exposure apparatus 100 of the present invention is configured toexpose a photo-resist layer 102 on a transparent substrate 101 forpatterning the photo-resist layer 102. In this case, the transparentsubstrate 101 may be a transparent glass substrate or a transparentflexible plastic substrate. The material of the photo-resist layer 102may be a positive resist material or a negative resist material. It isworth mentioning that, before exposing the photo-resist layer 102, theremay be one or more layer structures 103 between the photo-resist layer102 and the transparent substrate 101, and the one or more layerstructures 103 are preferably transparent structures for allowing lightrays to pass from the one or more layer structures 103 from thephoto-resist layer 102 to the transparent substrate 101.

Referring to FIG. 1 again, the exposure apparatus 100 of the presentembodiment can comprise an exposure light source 110, a mask 120 and areflective plate 130. The exposure light source 110 is configured toprovide light rays to the photo-resist layer 102 on the transparentsubstrate 101. The mask 120 is disposed between the exposure lightsource 110 and the transparent substrate 101 for allowing a portion ofthe light rays to pass, so as to pattern the photo-resist layer 102. Thereflective plate 130 is configured to reflect the light rays passingthrough the photo-resist layer 102 and the transparent substrate 101back to the photo-resist layer 102, so as to increase an exposed extentof the photo-resist layer 102, and thus a portion of the photo-resistlayer 102 designed to be patterned can be completely exposed forensuring the forming of a predetermined pattern.

Referring to FIG. 1 again, the exposure light source 110 of the presentembodiment may be a metal halide lamp, a mercury lamp, a fluorescentlamp, a UV lamp or a laser source for emitting exposure light rays. Theexposure light rays emitted from the exposure light source 110 arepreferably ultraviolet light rays or the light rays (such as laserlight) with a wavelength less than the ultraviolet light. The exposurelight source 110 can directly face to the transparent substrate 101 foremitting the light rays to the transparent substrate 101. In anotherembodiment, the exposure light rays emitted from the exposure lightsource 110 may be transmitted to the transparent substrate 101 throughan optical system (not shown) which is composed of a plurality of lens.

Referring to FIG. 1 again, the mask 120 of the present embodiment isdisposed at one side of the photo-resist layer 102 (such as an upside)and positioned between the exposure light source 110 and thephoto-resist layer 102 on the transparent substrate 101. The mask 120includes an opaque pattern 121 and at least one transparent opening (orslit) 122. The material of the opaque pattern 121 may be chromium (Cr)to shelter a portion of the light rays emitted from the exposure lightsource 110 for patterning the photo-resist layer 102. The mask 120 maybe directly close to a surface of the photo-resist layer 102. At thistime, a width (such as 2 um) of the transparent opening 122 may besubstantially equal to or similar to a width W (such as 2 um) of anexposed area on the surface of the photo-resist layer 102. In anotherembodiment, the exposure apparatus 100 may further comprise a projectionreduction lens system 150 disposed between the mask 120 and thetransparent substrate 101 for projecting the light rays passing throughthe mask 120 to the surface of the photo-resist layer 102. At this time,the width (such as 10 um) of the transparent opening 122 may be greatlylarger than the width W (such as 2 um) of the exposed area on the topsurface of the photo-resist layer 102. Moreover, the mask 120 can bepositioned to the photo-resist layer 102 on the transparent substrate101 by using an aligner 160.

Referring to FIG. 1 again, the reflective plate 130 of the presentembodiment is disposed at an opposite side (such a underside) of thephoto-resist layer 102 for reflecting the light rays passing through thephoto-resist layer 102 and the transparent substrate 101, so as to allowthe light rays to be reflected back to the photo-resist layer 102,thereby increasing the exposed extent of the photo-resist layer 102, aswell as preventing that a bottom portion (a portion close to thetransparent substrate 101) of the photo-resist layer 102 is exposedinsufficiently. Therefore, it is ensured that the photo-resist layer 102is completely exposed, and the exposed pattern of the photo-resist layer102 can meet the precise requirement of the predetermined pattern. Whenexposing the photo-resist layer 102, the reflective plate 130 ispreferably and substantially parallel to the photo-resist layer 102 onthe transparent substrate 101, so as to directly reflect the light rayspassing through the transparent substrate 101 back to the photo-resistlayer 102 in the total reflection manner, so as to enhance the precisionof the exposed pattern of the photo-resist layer 102. The reflectiveplate 130 includes a highly reflective material, such as Ag, Al, Au orwhite paint (such as titanium oxide) for reflecting the light rays. Thereflective plate 130 may be made of the highly reflective material (suchas metal) as one-piece. Alternatively, the highly reflective materialcan be coated on a plate (not shown) to form the reflective plate 130.In this embodiment, a reflective surface of the reflective plate 130 canbe a flat surface. That is, the reflective plate 130 can act as a planemirror.

In one embodiment, when exposing the photo-resist layer 102, thetransparent substrate 101 can be carried on the reflective plate 130. Atthis time, the bottom surface of the transparent substrate 101 cancontact with the reflective surface of the reflective plate 130. Inanother embodiment, a transparent plate can be disposed between thetransparent substrate 101 and the reflective plate 130 for carrying thetransparent substrate 101 and allowing the light rays to pass.

Referring to FIG. 1 again, the exposure method can comprise thefollowing steps: utilizing an exposure light source 110 to provide lightrays to the photo-resist layer 102, wherein the light rays provided bythe exposure light source 110 pass through the mask 120 to reach thephoto-resist layer 102; and utilizing a reflective plate 130 to reflectthe light rays passing through the photo-resist layer 102 and thetransparent substrate 101 back to the photo-resist layer 102.

For example, referring to FIG. 1 again, when applying the exposureapparatus 100 to a process for manufacturing the LCD panel, thetransparent substrate 101 may be the glass substrate, and a transparentelectrode layer (such as ITO layer) 103 desired to be patterned isformed between the photo-resist layer 102 and the transparent substrate101. When using the exposure apparatus 100 of the present embodiment toexpose the photo-resist layer 102, the exposure light source 110 canemit the light rays to the photo-resist layer 102 through the mask 120.Subsequently, the light rays passing through the photo-resist layer 102,the transparent electrode layer 103 and the transparent substrate 101are reflected back by the reflective plate 130 for increasing theexposed extent of the top portion of the photo-resist layer 102, so asto ensuring the photo-resist layer 102 to be exposed sufficiently. Thus,it can be avoided that the bottom portion of the photo-resist layer 102is not exposed completely due to a small line space or a highdepth-to-width ratio.

Referring to FIG. 2 and FIG. 3, FIG. 2 is a schematic diagram showing apatterned photo-resist layer according to the first embodiment of thepresent invention, and FIG. 3 is a schematic diagram showing an etchedtransparent electrode layer according to the first embodiment of thepresent invention. As shown in FIG. 2, after exposing the photo-resistlayer, a portion of the photo-resist layer 102 is removed off by adeveloping step for patterning the photo-resist layer 102. As shown inFIG. 3, subsequently, a portion of the transparent electrode layer 103which is not sheltered by the patterned photo-resist layer 102 isremoved off by an etching step. Subsequently, the patterned photo-resistlayer 102 is removed off, so as to achieve the patterned transparentelectrode layer 103.

With the use of the exposure apparatus 100 and the exposure method ofthe present invention, it is ensured that the photo-resist layer 102 canbe completely exposed, and thus the line space of the predeterminedpattern or the width of the transparent opening 122 of the mask 120 canbe reduced. In this embodiment, the line space of the predeterminedpattern or the width of the transparent opening 122 of the mask 120 canbe less than 3 um, and preferably less than or equal to 2 um.

Referring to FIG. 4, a schematic diagram showing an exposure apparatusaccording to a second embodiment of the present invention isillustrated. The exposure apparatus 200 of the second embodiment cancomprise an exposure light source 210, a mask 220 and a reflective plate230. The mask 220 is disposed between the exposure light source 210 andthe photo-resist layer 102 on the transparent substrate 101. Thereflective plate 230 is configured to reflect the light rays passingthrough the photo-resist layer 102 and the transparent substrate 101back to the photo-resist layer 102. The exposure apparatus 200 mayfurther comprise a projection reduction lens system 250 disposed betweenthe mask 220 and the transparent substrate 101 for projecting the lightrays passing through the mask 220 to the surface of the photo-resistlayer 102. Moreover, the mask 220 can be positioned to the photo-resistlayer 102 on the transparent substrate 101 by using an aligner 260. Incomparison with the first embodiment, the reflective plate 230 of thesecond embodiment includes a plurality of convex structures which faceto the transparent substrate 101. Therefore, the reflective convexsurfaces can act as convex mirrors.

Referring to FIG. 5, a schematic diagram showing an exposure apparatusaccording to a third embodiment of the present invention is illustrated.The exposure apparatus 300 of the third embodiment can comprise anexposure light source 310, a mask 320 and a reflective plate 330. Themask 320 is disposed between the exposure light source 310 and thephoto-resist layer 102 on the transparent substrate 101. The reflectiveplate 330 is configured to reflect the light rays passing through thephoto-resist layer 102 and the transparent substrate 101 back to thephoto-resist layer 102. The exposure apparatus 300 may further comprisea projection reduction lens system 350 disposed between the mask 320 andthe transparent substrate 101 for projecting the light rays passingthrough the mask 320 to the surface of the photo-resist layer 102.Moreover, the mask 320 can be positioned to the photo-resist layer 102on the transparent substrate 101 by using an aligner 360. In comparisonwith the first embodiment, the reflective plate 330 of the thirdembodiment includes a plurality of concave structures which face to thetransparent substrate 101. Therefore, the reflective concave surfacescan act as concave mirrors.

As described above, with the use of the exposure apparatus and theexposure method of the present invention, it is ensured that the portionof the photo-resist layer desired to be patterned can absorb enoughexposure energy, and the pattern qualifying for the predeterminedrequirement can be formed after the developing step. Therefore, by meansof the exposure apparatus and the exposure method of the presentinvention, the line space of the desired pattern can be reduced forpromoting the performance of electrical devices.

The present invention has been described with a preferred embodimentthereof and it is understood that many changes and modifications to thedescribed embodiment can be carried out without departing from the scopeand the spirit of the invention that is intended to be limited only bythe appended claims.

The invention claimed is:
 1. An exposure apparatus for exposing aphoto-resist layer on a transparent substrate, wherein a transparentelectrode layer is positioned between the photo-resist layer and thetransparent substrate, and the exposure apparatus comprises: a maskdisposed at one side of the photo-resist layer for patterning thetransparent electrode, wherein the mask includes at least onetransparent opening, and a width of the transparent opening is less than2 um; an exposure light source configured to provide light rays to thephoto-resist layer, wherein the light rays provided by the exposurelight source pass through the mask to reach the photo-resist layer; areflective plate disposed at an opposite side of the photo-resist layerfor reflecting the light rays passing through the photo-resist layer andthe transparent substrate back to the photo-resist layer, wherein thereflective plate is parallel to the photo-resist layer on thetransparent substrate when exposing it; and a projection reduction lenssystem disposed between the mask and the transparent substrate forprojecting the light rays passing through the mask to a surface of thephoto-resist layer, wherein the mask is positioned to the photo-resistlayer on the transparent substrate by using an aligner.
 2. The exposureapparatus according to claim 1, wherein a reflective surface of thereflective plate is a flat surface.
 3. The exposure apparatus accordingto claim 1, wherein the reflective plate includes a plurality of convexstructures.
 4. The exposure apparatus according to claim 1, wherein thereflective plate includes a plurality of concave structures.
 5. Anexposure apparatus for exposing a photo-resist layer on a transparentsubstrate, wherein a transparent electrode layer is positioned betweenthe photo-resist layer and the transparent substrate, and the exposureapparatus comprises: a mask disposed at one side of the photo-resistlayer for patterning the transparent electrode; an exposure light sourceconfigured to provide light rays to the photo-resist layer, wherein thelight rays provided by the exposure light source pass through the maskto reach the photo-resist layer; a reflective plate disposed at anopposite side of the photo-resist layer for reflecting the light rayspassing through the photo-resist layer and the transparent substrateback to the photo-resist layer; and a projection reduction lens systemdisposed between the mask and the transparent substrate for projectingthe light rays passing through the mask to a surface of the photo-resistlayer, wherein the mask is positioned to the photo-resist layer on thetransparent substrate by using an aligner.
 6. The exposure apparatusaccording to claim 5, wherein the mask includes at least one transparentopening, and a width of the transparent opening is less than 3 um. 7.The exposure apparatus according to claim 6, characterized in that: thewidth of the transparent opening is equal to or less than 2 um.
 8. Theexposure apparatus according to claim 5, characterized in that: areflective surface of the reflective plate is a flat surface.
 9. Theexposure apparatus according to claim 5, characterized in that: thereflective plate includes a plurality of convex structures.
 10. Theexposure apparatus according to claim 5, characterized in that: thereflective plate includes a plurality of concave structures.
 11. Theexposure apparatus according to claim 5, characterized in that: thereflective plate is parallel to the photo-resist layer on thetransparent substrate when exposing the photo-resist layer.
 12. Anexposure method for exposing a photo-resist layer on a transparentsubstrate, wherein a transparent electrode layer is positioned betweenthe photo-resist layer and the transparent substrate, and the exposuremethod comprises the following steps: utilizing an exposure light sourceto provide light rays to the photo-resist layer, wherein the light raysprovided by the exposure light source pass through the mask to reach thephoto-resist layer for patterning the transparent electrode; andutilizing a reflective plate to reflect the light rays passing throughthe photo-resist layer and the transparent substrate back to thephoto-resist layer; wherein a projection reduction lens system isdisposed between the mask and the transparent substrate for projectingthe light rays passing through the mask to a surface of the photo-resistlayer, and the mask is positioned to the photo-resist layer on thetransparent substrate by using an aligner.
 13. The exposure methodaccording to claim 12, wherein the mask includes at least onetransparent opening, and a width of the transparent opening is less than3 um.
 14. The exposure method according to claim 12, wherein thereflective plate is parallel to the photo-resist layer on thetransparent substrate when exposing the photo-resist layer.
 15. Theexposure method according to claim 12, wherein, when utilizing thereflective plate to reflect the light rays, the transparent substrate iscarried on the reflective plate.